The present invention is addressed to improvements in urological catheters to minimize the possible injury to the urethra and bladder of a patient. More particularly, the present invention provides an improved construction for a urological catheter to minimize frictional contact with the urethra during movement therealong; to enhance the necessary advancing movement of the catheter along the urethra through magnetic means for propelled movement or bestow directionability to the advancing tip and to utilize distention of a retention balloon as an actuator of a mechanism employed to expose the drainage lumen in the catheter and, if desired, operate a retention mechanism for in situ support in the urethra of a segmented portion of the catheter while the disjoined part of the drainage lumen is withdrawn from the urethra.
The Foley catheter is a well-known form of a urological catheter employing a retention balloon that is inflated after insertion into a patient's bladder. The catheter is primarily used to drain the human bladder when there is an obstruction by the prostate gland and other causes, such as after surgery and to treat urinary inconvenience of senility and paralytic conditions of the body. A urological catheter is frequently used during post-surgery recovery, particularly after surgical removal of the prostate to alleviate a blockage in the area of the bladder. The catheter is used in other instances where the need to alleviate a blockage arises, even though the patient's natural sphincter is functionally useful but rendered inoperative due to the presence of a catheter.
Problems and shortcomings arise out of the use of the Foley catheter as presently manufactured. The catheter must be advanced along the human urethra by pushing blindly which sometimes tears the lining of the urethra and causes bleeding, infection and scar formation in the urethra. The catheter typically has drainage eyelets in a blunt, solid tip which presents a relatively large surface area causing adverse frictional contact with the urethra. Such a tip is not hydrodynamically efficient. Near the distal end, the two eyelets in the tip portion of presently-available catheters weaken the tip, permitting it to buckle during movement along the urethra. This buckling is believed to occur because of the aligned arrangement of the eyelets at diametrically-opposite sites which brings about a dramatic symmetrical weakening to the side wall of the tip. When the tip buckles, protruding edges develop, particularly at the sites of the eyelets causing a scratching of the lining of the urethra which, in turn, produces bleeding and injury. The cuff or retention balloon of the catheter is not biogenetically shaped to conform to the shape of the bladder neck. After distention of the balloon, the tip of the catheter protrudes therefrom to an excessively large distance such that injury to the bladder wall is possible as the wall of the bladder contacts the protruding tip. Moreover, the drainage eyelet openings in the tip of the catheter are spaced from the wall of the inflated retention balloon, thus causing an obstruction preventing complete drainage of the bladder.